beedb/include/execution/predicate_matcher.h

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2022-04-04 20:25:01 +02:00
/*------------------------------------------------------------------------------*
* Architecture & Implementation of DBMS *
*------------------------------------------------------------------------------*
* Copyright 2022 Databases and Information Systems Group TU Dortmund *
* Visit us at *
* http://dbis.cs.tu-dortmund.de/cms/en/home/ *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR *
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, *
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR *
* OTHER DEALINGS IN THE SOFTWARE. *
* *
* Authors: *
* Maximilian Berens <maximilian.berens@tu-dortmund.de> *
* Roland Kühn <roland.kuehn@cs.tu-dortmund.de> *
* Jan Mühlig <jan.muehlig@tu-dortmund.de> *
*------------------------------------------------------------------------------*
*/
#pragma once
#include <memory>
#include <table/schema.h>
#include <table/tuple.h>
namespace beedb::execution
{
/**
* Interface for predicate matcher. The predicate matcher
* takes one or two tuples and compares them with a constant
* or a value from another tuple.
*/
class PredicateMatcherInterface
{
public:
enum Comparison
{
EQ,
LE,
LT,
GE,
GT,
NEQ
};
virtual ~PredicateMatcherInterface() = default;
virtual bool matches(const table::Tuple &tuple) = 0;
virtual bool matches(const table::Tuple &left, const table::Tuple &right) = 0;
virtual std::unique_ptr<PredicateMatcherInterface> clone() = 0;
};
/**
* The given tuple will always match.
*/
class AlwaysTrueMatcher final : public PredicateMatcherInterface
{
public:
AlwaysTrueMatcher() = default;
~AlwaysTrueMatcher() override = default;
bool matches(const table::Tuple &) override
{
return true;
}
bool matches(const table::Tuple &, const table::Tuple &) override
{
return true;
}
std::unique_ptr<PredicateMatcherInterface> clone() override
{
return std::make_unique<AlwaysTrueMatcher>();
}
};
/**
* Takes two predicate matchers p1 and p2 and connects them using AND.
* Tuple matches when p1 AND p2 matches.
*/
class AndMatcher final : public PredicateMatcherInterface
{
public:
AndMatcher(std::unique_ptr<PredicateMatcherInterface> &&left, std::unique_ptr<PredicateMatcherInterface> &&right)
: _left(std::move(left)), _right(std::move(right))
{
}
~AndMatcher() override = default;
bool matches(const table::Tuple &tuple) override
{
return _left->matches(tuple) && _right->matches(tuple);
}
bool matches(const table::Tuple &left, const table::Tuple &right) override
{
return _left->matches(left, right) && _right->matches(left, right);
}
std::unique_ptr<PredicateMatcherInterface> clone() override
{
return std::make_unique<AndMatcher>(_left->clone(), _right->clone());
}
private:
std::unique_ptr<PredicateMatcherInterface> _left;
std::unique_ptr<PredicateMatcherInterface> _right;
};
/**
* Takes two predicate matchers p1 and p2 and connects them using OR.
* Tuple matches when p1 OR p2 matches.
*/
class OrMatcher final : public PredicateMatcherInterface
{
public:
OrMatcher(std::unique_ptr<PredicateMatcherInterface> &&left, std::unique_ptr<PredicateMatcherInterface> &&right)
: _left(std::move(left)), _right(std::move(right))
{
}
~OrMatcher() override = default;
bool matches(const table::Tuple &tuple) override
{
return _left->matches(tuple) || _right->matches(tuple);
}
bool matches(const table::Tuple &left, const table::Tuple &right) override
{
return _left->matches(left, right) || _right->matches(left, right);
}
std::unique_ptr<PredicateMatcherInterface> clone() override
{
return std::make_unique<OrMatcher>(_left->clone(), _right->clone());
}
private:
std::unique_ptr<PredicateMatcherInterface> _left;
std::unique_ptr<PredicateMatcherInterface> _right;
};
/**
* Compares a specific column in a tuple with a constant.
*/
template <PredicateMatcherInterface::Comparison C> class AttributeValueMatcher final : public PredicateMatcherInterface
{
public:
AttributeValueMatcher(const table::Schema::ColumnIndexType schema_index, table::Value &&value)
: _schema_index(schema_index), _value(std::move(value))
{
}
AttributeValueMatcher(const table::Schema::ColumnIndexType schema_index, const table::Value &value)
: _schema_index(schema_index), _value(value)
{
}
~AttributeValueMatcher() override = default;
bool matches(const table::Tuple &tuple) override
{
if constexpr (C == EQ)
{
return tuple.get(_schema_index) == _value;
}
else if constexpr (C == LE)
{
return tuple.get(_schema_index) <= _value;
}
else if constexpr (C == LT)
{
return tuple.get(_schema_index) < _value;
}
else if constexpr (C == GE)
{
return tuple.get(_schema_index) >= _value;
}
else if constexpr (C == GT)
{
return tuple.get(_schema_index) > _value;
}
else
{
return tuple.get(_schema_index) != _value;
}
}
bool matches(const table::Tuple &, const table::Tuple &) override
{
return false;
}
std::unique_ptr<PredicateMatcherInterface> clone() override
{
return std::make_unique<AttributeValueMatcher<C>>(_schema_index, _value);
}
protected:
const table::Schema::ColumnIndexType _schema_index;
const table::Value _value;
};
/**
* Compares two columns in a tuple or one column of two tuples.
*/
template <PredicateMatcherInterface::Comparison C> class AttributeMatcher final : public PredicateMatcherInterface
{
public:
AttributeMatcher(const table::Schema::ColumnIndexType schema_index_left,
const table::Schema::ColumnIndexType schema_index_right)
: _schema_index_left(schema_index_left), _schema_index_right(schema_index_right)
{
}
~AttributeMatcher() override = default;
bool matches(const table::Tuple &tuple) override
{
if constexpr (C == EQ)
{
return tuple.get(_schema_index_left) == tuple.get(_schema_index_right);
}
else if constexpr (C == LE)
{
return tuple.get(_schema_index_left) <= tuple.get(_schema_index_right);
}
else if constexpr (C == LT)
{
return tuple.get(_schema_index_left) < tuple.get(_schema_index_right);
}
else if constexpr (C == GE)
{
return tuple.get(_schema_index_left) >= tuple.get(_schema_index_right);
}
else if constexpr (C == GT)
{
return tuple.get(_schema_index_left) > tuple.get(_schema_index_right);
}
else
{
return tuple.get(_schema_index_left) != tuple.get(_schema_index_right);
}
}
bool matches(const table::Tuple &left, const table::Tuple &right) override
{
if constexpr (C == EQ)
{
return left.get(_schema_index_left) == right.get(_schema_index_right);
}
else if constexpr (C == LE)
{
return left.get(_schema_index_left) <= right.get(_schema_index_right);
}
else if constexpr (C == LT)
{
return left.get(_schema_index_left) < right.get(_schema_index_right);
}
else if constexpr (C == GE)
{
return left.get(_schema_index_left) >= right.get(_schema_index_right);
}
else if constexpr (C == GT)
{
return left.get(_schema_index_left) > right.get(_schema_index_right);
}
else
{
return left.get(_schema_index_left) != right.get(_schema_index_right);
}
}
std::unique_ptr<PredicateMatcherInterface> clone() override
{
return std::make_unique<AttributeMatcher<C>>(_schema_index_left, _schema_index_right);
}
[[nodiscard]] table::Schema::ColumnIndexType left_index() const
{
return _schema_index_left;
}
[[nodiscard]] table::Schema::ColumnIndexType right_index() const
{
return _schema_index_right;
}
protected:
const table::Schema::ColumnIndexType _schema_index_left;
const table::Schema::ColumnIndexType _schema_index_right;
};
} // namespace beedb::execution